Stacking method

Abstract

Stacking apparatus and method for generally flat objects, particularly useful for the stacking of magazines by zip code. According to the invention, a continuous input stream of the objects is alternately diverted in preselected numbers pursuant to a shift signal to first and second hoppers or bins wherein the objects are deposited in stacks, the stacks when completed being alternately ejected from the hoppers onto common conveyor means whereon they are merged into a single output series of stacks. In one form of the invention an input feeder receives the output flow of magazines from a labeler; a vertically shiftable separator alternately directs sequences of the generally flat objects to upper and lower feed conveyors which in turn alternately feed the sequences of objects to side-by-side hoppers. "Live" rollers moving at right angles to the feed conveyors underlie and extend as stack output conveyor means from the hoppers. In an automatic zip code stacking embodiment of the invention, the shift signal is provided without requiring delay means from an optical reader located on the labeler that feeds the stacking apparatus, shift registration for diverting the objects being provided in the label printout wherein a label is marked for optical reading for a zip code change that is located a fixed number of labels behind the zip code change label in the sequence.

I claim: 
     
       1. The method of diverting labeled objects moving rapidly in succession in a continuous stream to form a plurality of streams for stacking purposes, comprising employing an electrical shift signal from the sensing of indicia upon predetermined labels to divert said objects selectively to one of said plurality of streams, and locating the label a fixed number of labels behind the label in line to be first diverted by the corresponding shift. 
     
     
       2. The method of claim 1 and directing said labeled objects into respective first and second stacks of said objects at respective first and second stacks of said objects at respective first and second stacking stations one beyond the other on approximately the same level, removing each stack laterally from its respective station onto an output conveyor before completion of the next successive stack at the other station so as to make each station open for the commencement of a new stack, and merging said stacks being alternately removed from said stations successively onto a single output conveyor with a predetermined overlap of the merging cycles while a new stacking sequence is occurring at one of the stations. 
     
     
       3. The method of claim 1 comprising directing said labeled objects into first and second stacks of said objects at first and second stacking stations, removing a completed stack from one of said stations before completion of the stack at the other station, and employing said electrical shift signal to initiate said removal upon diverting of said stream to said other stacking station by said signal. 
     
     
       4. The method of claim 3, wherein each of said shift signals is delayed in its employment to initiate the removal of a respective stack to permit completion of the feeding of that stack.